Direct epoxidation process using pre-treated titanium zeolite

Abstract

The invention is a process for epoxidizing an olefin with hydrogen and oxygen in the presence of a catalyst comprising a noble metal and pretreated titanium zeolite. Titanium zeolite pretreatment comprises contacting the titanium zeolite with a leaching agent prior to use in epoxidation. Surprisingly, the process using the pretreated titanium zeolite shows decreased ring-opening to unwanted glycols and glycol ethers.

I claim:  
     
       1. A process for producing an epoxide comprising reacting an olefin, oxygen, and hydrogen in the presence of a catalyst comprising a noble metal and pre-treated titanium zeolite, wherein the pre-treated titanium zeolite is formed by contacting a titanium zeolite with a leaching agent such that greater than 0.1 percent of the titanium is removed from the titanium zeolite. 
     
     
       2. The process of  claim 1  wherein the leaching agent is a combination of hydrogen peroxide and a chelating organic compound. 
     
     
       3. The process of  claim 2  wherein the chelating organic compound is selected from the group consisting of glycols, carboxylic acid compounds, and hydroxy ketone compounds. 
     
     
       4. The process of  claim 1  wherein the leaching agent is selected from the group consisting of chelating organic compounds and mineral acids. 
     
     
       5. The process of  claim 4  wherein the chelating organic compound is selected from the group consisting of glycols, carboxylic acid compounds, and hydroxy ketone compounds. 
     
     
       6. The process of  claim 1  wherein the titanium zeolite is titanium silicalite. 
     
     
       7. The process of  claim 1  wherein the titanium zeolite is TS-1. 
     
     
       8. The process of  claim 1  wherein the catalyst is comprised of from 0.01 to 5 weight percent noble metal. 
     
     
       9. The process of  claim 1  wherein the noble metal is palladium. 
     
     
       10. The process of  claim 1  wherein the olefin is a C 2 -C 6  olefin. 
     
     
       11. The process of  claim 1  wherein the olefin is propylene. 
     
     
       12. The process of  claim 1  further comprising a solvent selected from the group consisting of methanol, ethanol, isopropanol, and tert-butanol, and water. 
     
     
       13. The process of  claim 1  further comprising a carrier gas. 
     
     
       14. The process of  claim 13  wherein the carrier gas is selected from the group consisting of helium, neon, argon, nitrogen, carbon dioxide, and C 1-8 , saturated hydrocarbons. 
     
     
       15. The process of  claim 13  wherein the carrier gas is propane.